1 Definition
1.1 Definition
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Trachyandesite is an extrusive igneous rock.
1.2 History
1.2.1 Origin
1.2.2 Discoverer
John Peter Salley
Unknown
1.3 Etymology
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
1.4 Class
Sedimentary Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock